The present invention relates to a combination lock, and more particularly, to a combination lock which may be opened without viewing the lock and which includes a variable-sized shackle.
Combination locks are well known in the art. A combination lock typically includes a body, which includes tumblers, locking members and a combination dial. Extending from the body is an inverted U-shaped shackle with one leg slightly shorter than the other leg, which is engaged with the locking members to latch and release the shackle relative to the lock body. When released, the shackle moves upwardly out of the body to achieve relative reciprocal movement. The short end of the shackle will then pivot to open only after vertically clearing the lock body. One problem with these types of reciprocating shackle combination locks is the shackle is exposed and thus easy to cut using bolt cutters or other tools. Another problem with these types of locks is the combination dial must be viewed in order to enter the combination and open the lock. If the lock is in a position in which the dial is not visible or if it is dark, the lock is difficult to open.
Another type of lock well known in the art is the gun lock or gun trigger lock. The detachable gun lock typically includes a back plate with a post which extends through the trigger guard of the gun in front of the trigger, and a combination or key actuated bolt which cooperates with the post to secure the post between the trigger guard and the trigger. A problem with the dial combination gun lock is in an emergency it may take several attempts to correctly enter the combination and open the lock. If it is dark or if the gun owner requires corrective lenses to be able to see and is not wearing them, the dial may not be readily seen. This problem is especially difficult at night when the gun owner is awakened by the sound of an intruder. The gun owner may not want to turn on a light in order to read the combination dial. Another problem with gun trigger locks is the lock is often clamped to the trigger guard with pressure. If the friction between the lock and the trigger guard is overcome, the trigger may be pulled and the gun fired if loaded. With a key-actuated trigger lock, if the key is located, anyone may open the lock and use the gun. Conversely, if the key is lost or cannot be located in an emergency, the lock cannot be opened when necessary.
The present invention provides a combination lock which may be used in place of prior art shackle locks and gun locks. The combination lock includes indexed tumbler buttons to enter the combination without having to view the lock. A variable-sized locking pin is protected within the protective housing and occupies the space behind a trigger on a gun or the eye of a latch plate. The tumbler buttons may be activated separately or simultaneously in any sequence to operate the combination lock.